1. Field of the Invention
The present invention relates to a device intended in particular to equip an agricultural machine so as to allow the device to be brought from a work position into another position or vice versa, said agricultural machine comprises a hitching structure by means of which it is intended to be hitched to a hitching device of a motor vehicle, said hitching structure comprising an upper hitching point and at least one lower hitching point.
The combination of such a device with an agricultural machine, especially a cutting machine, comprising:
a hitching structure intended to be hitched to a hitching device of a motor vehicle and comprising an upper hitching point and at least one lower hitching point;
a cutting mechanism connected directly or indirectly to the hitching structure and intended to assume:
at least one work position;
at least one transport position, and
at least one other intermediate position;
a first device allowing said cutting mechanism to be brought from a work position into an intermediate position or vice versa;
a second device allowing said cutting mechanism to be brought into a transport position; and
a third device intended to lighten the cutting mechanism in the work position,
so as to allow the cutting machine to be brought from a work position into another intermediate position or vice versa.
2. Discussion of the Background
An agricultural machine equipped with such a device is known. This agricultural machine is a mower comprising a cutting mechanism connected to a hitching structure by means of a carrying beam. This carrying beam is connected on the one hand to the central part of the cutting mechanism by means of a first articulation with an approximately horizontal longitudinal axis pointing in the direction of forward travel and, on the other hand, to the hitching structure by means of a second articulation of approximately horizontal longitudinal axis.
A lifting device comprising a hydraulic ram allows the cutting mechanism and the carrying beam to be pivoted upward about the second articulation. For this, the hydraulic ram is connected, on the one hand, to the carrying beam and, on the other hand, to the hitching structure, and is intended to communicate with a hydraulic unit of a motor vehicle to which the mower is intended to be connected.
This mower can occupy various positions, including a work position, in which the cutting mechanism rests on the ground, a transport position in which the cutting mechanism extends approximately vertically upward and an intermediate position in which the cutting mechanism extends somewhat above the level of the ground.
To achieve this, the hydraulic ram pivots more or less the cutting mechanism and the carrying beam upward about the second articulation.
The cutting mechanism is driven by means of a transmission device comprising a first telescopic transmission shaft with universal joints which is connected on the one hand to a power take-off of the motor vehicle and on the other hand to a transmission casing of the mower, which casing transmits the movement to the cutting mechanism via a second transmission shaft.
A mower of this kind can swiftly be brought from a work position into an intermediate position or vice versa, and this makes operations at the end of the plot, for example, easier.
Furthermore, when changing into the intermediate position, the hitching structure, to which the transmission casing is connected, retains its initial position, and this allows the first telescopic transmission shaft with universal joints always to operate under acceptable conditions.
However, this mower does have a major drawback. It can be seen that the second articulation, that connects the carrying structure to the hitching structure, is situated in close proximity to the cutting mechanism, and this results in insufficient space between the cutting mechanism and the ground when said cutting mechanism extends in an intermediate position. In this case, there is a risk, during operations at the end of the plot, that the swaths of fodder already formed by the mower may be disturbed. Furthermore, the slightest unevenness of the ground risks causing a collision between the cutting mechanism and said ground, with the risk of damaging the mower.
Finally, an intermediate position, in which the ground clearance of the cutting mechanism is insufficient, not only forces the operator to pay particular attention to the mower during operations at the end of the plot, but also forces him to carry out additional operations in order to avoid damaging said mower.
The object of the present invention is to overcome the drawbacks of this known mower, while at the same time maintaining a swift change to the intermediate position and good working conditions for the transmission device.
To this end, the device according to the present invention, intended to equip an agricultural machine and allowing it to be brought from a work position into another position or vice versa, said agricultural machine comprising a hitching structure by means of which it is intended to be hitched to a hitching device of a motor vehicle, and said hitching structure for its part comprising an upper hitching point and at least one lower hitching point, is one wherein there is provided a second lower hitching point connected to said device and wherein said hitching structure can be moved with respect to said second lower hitching point by means of said device.
The present invention also relates to a cutting machine comprising:
a hitching structure intended to be hitched to a hitching device of a motor vehicle and comprising an upper hitching point and at least one lower hitching point;
a cutting mechanism connected directly or indirectly to the hitching structure and intended to assume:
at least one work position;
at least one transport position, and
at least one other intermediate position;
a first device allowing said cutting mechanism to be brought from a work position into an intermediate position or vice versa;
a second device allowing said cutting mechanism to be brought into a transport position;
a third device intended to lighten the cutting mechanism in the work position.
Such a device, particularly when it is equipping a cutting machine like the one described hereinabove, advantageously allows the hitching structure to be pivoted upward about the lower hitching point belonging to said hitching structure so as to raise the cutting mechanism and bring it from a work position into another intermediate position, or vice versa.
The invention also relates to the following features taken in isolation or in any technically feasible combination:
the device comprises an operating element allowing the hitching structure to be moved with respect to the second lower hitching point and a holding element allowing the motor vehicle to pull or to push the agricultural machine during work;
the operating element is connected directly or indirectly to the hitching structure and is connected directly or indirectly to the second lower hitching point;
the holding element is a draft rod connected on the one hand directly or indirectly to the hitching structure by means of a first articulation the longitudinal axis of which is at least approximately horizontal and transversal to the direction of forward travel;
the second lower hitching point is connected to the draft rod;
the operating element comprises an operating ram connected on the one hand to the hitching structure by means of a second articulation and on the other hand to the draft rod by means of a third articulation;
the device is intended to come from a position other than the work position into the work position under the effect of the weight of the agricultural machine;
the device additionally comprises a fixed structure intended to be fixed, on the one hand, to the hitching structure and on the other hand supporting the draft rod by means of the first articulation;
to define the maximum intermediate position corresponding to maximum pivoting of the hitching structure about the lower hitching point belonging to said hitching structure, the position of the second lower hitching point furthest from the hitching structure is limited by means of a stop;
the third device intended to lighten the cutting mechanism comprises an energy accumulator connected directly or indirectly to the hitching structure and connected directly or indirectly to the cutting mechanism;
the cutting machine comprises a carrying beam connected on the one hand to the cutting mechanism by means of a fourth articulation and on the other hand directly or indirectly to the hitching structure by means of a fifth articulation and of a sixth articulation;
the energy accumulator comprises a ram and a pressure accumulator, said ram being connected on the one hand directly or indirectly to the hitching structure and on the other hand being connected to said carrying beam by means of a seventh articulation;
to increase the ground clearance of the cutting mechanism without thereby further pivoting the hitching structure about the lower hitching point thereof, the first device, allowing the cutting mechanism to be brought from a work position into an intermediate position or vice versa, is combined with the third device intended to lighten the cutting mechanism in the work position;
the first device allowing the cutting mechanism to be brought from a work position into an intermediate position or vice versa controls the third device intended to lighten said cutting mechanism so as to pivot the hitching structure about the lower hitching point thereof while at the same time pivoting the carrying beam and the cutting mechanism about the fifth articulation;
the operating ram of the first device is in communication with the ram of the energy accumulator of the third device;
the operating ram of the first device comprises two chambers, the first chamber being intended to communicate with a hydraulic unit of the motor vehicle and the second chamber being in communication with the single chamber of the ram of the energy accumulator;
there is provided a first valve intended to allow or to prevent communication between the hydraulic unit of the motor vehicle and the first chamber of the operating ram;
there is provided a second valve intended to allow or to prevent communication between the hydraulic unit of the motor vehicle and the second chamber of the operating ram, the pressure accumulator and the single chamber of the ram of the energy accumulator, which in particular allows the amount of lightening of the cutting mechanism to be adjusted;
there is provided a means allowing fluid to pass only toward the first chamber of the operating ram and limiting the flow rate of the fluid between said first chamber and the hydraulic unit of the motor vehicle, this allowing rapid deployment of the operating ram in order to bring the cutting mechanism swiftly into the intermediate position and, by contrast, less swift retraction of said operating ram in order to bring said cutting mechanism into the work position less abruptly;
the second device allowing said cutting mechanism to be brought into a transport position comprises another ram allowing the cutting mechanism to be pivoted from an intermediate position into a transport position or vice versa about the sixth articulation;
the other ram of the second device comprises:
a first chamber intended to communicate with the hydraulic unit of the motor vehicle; and
a second chamber intended to communicate with the hydraulic unit of the motor vehicle via a third valve;
the third valve comprises or is combined with a second means which, when said third valve is in one position, allows fluid to pass only toward the second chamber of the other ram and prevents outlet therefrom;
the third device intended to lighten the cutting mechanism comprises an additional ram connected on the one hand directly or indirectly to the hitching structure and on the other hand to the ram of the energy accumulator;
the additional ram and the ram of the energy accumulator comprise a common ram rod and the body of said additional ram is connected directly or indirectly to the hitching structure;
the additional ram comprises another single chamber intended to communicate with the hydraulic unit of the motor vehicle and the first chamber of the operating ram;
the first and second chambers of the operating ram, the single chamber of the energy accumulator, the first and second chambers of the other ram of the second device and, as appropriate, the chamber of the additional ram are set out relative to one another in such a way as to form a system intended to communicate with the hydraulic unit of the motor vehicle by means of a single supply.